Latch lock for mine cars



May 22, 1945 R. A. SHIELDS 2,376,826

LATCH LOCK FOR MINE CARS Filed sept. 1, 1942 2 sheets-sheet 1 May 22, 1945- R. A. sHlELDs 2,376,826

LATCH LOCK FOR MINE CARS Filed Sept. l, 1942 2 Sheets-Sheet 2 INVENTOR 6 .mM-@mudas ATTORNEY Patented May 22,` 1945 UNITEDA STATES PATENrjfoIFFlcE 2,375,826 l LATCH LOCK Fon MINE oARs Robert- A. Sli;lelds','Bloomsburg, Pa., .assignor to American Car and Foundryv Company, New York, N. Y., a corporation of-'New Jersey o Application-September 1, 1942, Serial No. 456386?? Col. 10a-2861) reclaim.

This invention relates in general to latch locks for mine and industrial 4cars and in particular toau-tomatic .latch locks for use with drop bottom mine cars. i

Drop` bottom mine cars as built for a number of years have utilizedza hook and arm arrangement to. lock the rear doorI of the` car and permit its tripping at the dumpfpit. However, considerable trouble has been due. to the fact that the latch was operated. in the mine by stone or lumps lof coal'wzhich may'have .fallen along. the track. Operation of the latch inthe mine. necessitated neitherwa complete unloading of thecar or a dragging/of `the car with 4door down over the ties, switches, etc. In :any .case considerable dew lay and' inconvenience was caused whenever a latch was accidentally operated. Such delay and inconvenience is multiplied many times in case the'so-called 1-2-#3 car is used', that is, a car in which alli doors -d'rop when'the rear latch is operated and drag ori-the ties until ltlmlirstdocr .reaches the pit edge. Recently lock-ing dogs have been used toV prevent' operation of' the hook arm, but frequentlyy these dogs vibrate to an oil. position and required the presence of "an extra man at the dump stationv for* the sole purpose of operating the dogs. Frequently the operator would forget Ytoy throw the dog tothe locked position, with the result that the hook arm was not locked and they delays due to accidentally dumped doorsv still occurred. It is an object, therefore, of the present' invention to providel an automatic safety latch for the main latch or hook arm of a drop bottom mine car. v

A further object of the invention is the provision of a latch for theV rear door of'a drop bottom mine car in which the latch partsmustmove substantially simultaneously in two directions in orderto unlatch the door.

A still further object. ofthe. invention is the provision of an automaticallyl operated. safety latch movable by a thrust `acting.substantially normal to the. car side..y f A yet. further object of theinvention is the provision of' a latch for drop. bottom mine cars which 'can be operated to 'areleased position only by independent forces acting substantially at.

Fig. 2. is .an end view ofthe car with the improved latch arrangement; Fig. 3 is an end View with `parts ofthe latch mechanism in section invorder to betterdiscl-os'e the construction;

Fig. 4 is a plan view of thelatch and trackside ingv a slight modication, and y Fig. 7 is a sectional view taken substantially on line 'l--l yof Fig. 6. ,i i Referring now to the drawings in detail, it will be seen that'a min-e car of `more or less-conventional construction. has been disclosed. The car is constructed Withsides 2- attached to and supported by sills 4` andv bracingl gussets 6. The side walls are joinedby fa; frontend wall 8 and a rear end` Wall I0, whilethe sills are joined together .and tothe end walls by front and rear bumpers l2 and Hlv respectively. The car is supportedon tracks' T by wheel-s W which project into the lading body of the car Iand arey covered Aby wheel hoods Hi. The space-between theA side sills"y is closed by drop bottom doors I8, 9l and 20 located pivoted'as at32 by means' of Harbracket 34- fastened rspectively adjacent the "front, intermediate and rear portions `of the car. Tnesc'doors ar'ehin'ged by hinge rods 22 carried by the side sills and have their adjacent edges engaging so as to form al substantially continuous bottom when the doors are closed. The' rear dooris providedl with a hook lug' or tongue 24 extending rearwardly from the door and'adapted tobeengaged by a hook H;

- The hook H, asshoWn; in Figs?. lt'o 5inclusi`ve.

is fastened by any suitable means, such as rivets 26, to the vertically extending leg 2.8V of an langle for-rnv member having the other leg 3U,- positionedv to the endv Wall` of the-car.v v'The hookarm and hookV are constantly urgedv toward latched posi'- tion bym-cans ci a spring 3'6 guided by bolt 38, all as clearly shown in Fig.'2. i The hookv arm extends laterallythrough a sloty formed in end wall brace 4!)` and has` its outer end reinforced by meansiof anangle having verticalleg. 42 and horizontallleg' 44 so arranged and attached to legs 30j and` 2% as to form a. box section lonthe hook arm outwardly of the hookfI-I. As most clearly shown in Fig. 3f a` backing plated-G is welded or otherwis-e secured. in place within the box. section endl of the hoo-k arm and forms an abutment for one end of a spring 50, the other `end of which ts within a cup like member 52 slidable within thel box like'section of -the hook arm. This cup likei member 52 bears against the lower end of safety latch bar 54 pivoted as at 56 on upstanding earsz 58 welded or otherwise secured to the hook armI on either side of a slot E formed in the horizontal: leg 90. Movement of the safety latchV bar is con` troll-ed bya plunger orlatch operator 62 slidably mounted within the-box section hook arm and held in place by a bolt yor rivet 64 extendingv through the legs 28 and 42 of the angles forming the boX section end of the hook arm. A'slot (itisV formed in the plunger in order that it may move inwardly over the bolt or rivet 64. They custom# ary guide 68 for the hook arm end is modied; by forming an additional offset therein as at 10H in order to form a keeper beneath which the: upper end of the safety latch bar may swingorder to prevent lifting of the hook arm. The` guide strap is riveted orotherwise secured to the 'car by short rivet 12 and' longrivet 14. The

lower end 16 of the guide strap maybe either directly attached to the end wall of the car'or twisted to fit underneath the sloping portion of the sidewings as clearly shown in Fig.-4.

It will be obvious from the preceding that the safetylatch has been'shown as applied to a substantially conventional drop bottom mine car with the conventional hook arm modiedslightly tol accommodate the safety latch. It will also be: obvious that the car can Yoperate Yover the regular trackag'e and function exactlyv as a standard car would now function. In order to operate the safety latch, however, the hook vtripping ramp R locatedv adjacent the forward edge of the pit P in some cases it may be desirable to eliminate the tripping ramp R and this may be accomplished as shown in'Figs. 6 and 7 wherein all parts duplicating those of Figs. 1 to 5 have been indicated by the same numerals. In this modication the hook H is pivotally mounted on Lleg 28 by means of a pivot, bolt or other device 99.

' which extends through a slot 96 formed in the hook. A spring 98 is provided having one end -`bearing beneath the leg 30 of the angle formed is modified lby addition of a plate 18. This plate is attached to the inclined portion 80 ofthe ltripping ramp. and is provided with an approach surface 82 anda curved leaving surface 84 with the surface intermediate these surfaces of suiiicient` width' and inclination as' to hold the plunger 62 in its innermost position within the box like sectionA of thehook arm. v As clearly shown in Fig. 2,43 asthe car would `move toward the dumping pit in the direction of the arrow of Fig. 1, the plunger 62 would strike the approach surface 82. and vbe moved inwardly and held'inwardly by the intermediate'surface, while theinclined part 8'0 of the ramp R causedthe hook arm to be' raised, thus` releasing the tongue 24'A of the rearmost door. Movement of the vplunger 62 inwardly will, of course, compress spring 50 and Irock'the safety` latch'bar 54 so as to bring the upper -end ofthe bar' from beneaththe ledge 10 'of the guide strap.'`

l' After the lading in the car has dumped the doors are closed by inclined rails 86 and in order that the hook arm may again engage the tnogue `24, it is necesary to providea second hook arm tripping rampR located adjacent the far end of the dumping pit as shown inFig. 5. Since this tripping ramp is identical with that at the approach end of the pit, the same numerals have vbeen applied but with a prime attached thereto. -It will. be seen from'r Fig. 5 that the end of the doorclosing arm 86 is sufficiently long as to hold the rearmost door closed until `the hook arm has dropped on? of the` operating ramp R and fallen into the i door engaging and latched position shown in 1 Fig. 3.' From the preceding it will be seen that the standard installation need be modified only ,v tothe extent of adding the safety latch to the hook arms and providing the operating plates 18 on the tripping ramps Rand adding asimilarly equipped ramp' R' at the leaving end of the pit,

hook arm .and the other end bearing against a shoulder formed on the hook H. This spring is the door tongue 24 riding along the 'incline 99 of the hook as the rear'door was forced closed by. the closing ramp 86. As'soon as the door israised sufficiently the hook would be snapped toits fullv line position vby the springr98"a`ndthe door would be `fully latched. y f

It will be. seenthat it is doors to be unlocked as in' the past by 'merely a lifting force applied to the hookarm, since the liftingof the hookarm is prevented due to the safety latchbar 54 acting as a ystrut-positioned between the ledge'l of'the: guide strap and the hook. arm. Movement ofthe `safety latch to a released position will not of itself release the Vdoor but will only move the safety latch from beneath the over-hangxl. In order to release the rear door and permit movementsof the hook armfto the position'shown by line and dash of Figs. 2 and 4 it is necessary for the plunger to be moved inwardlyprior to a vertical liftingof the hoo'k arm. Furthermore,4 the plunger must be held in atleast until the hook arm has liftedY a consid erable amount, otherwise thesaietyA latch would lagain engage beneath1the-1edge 1U. Inother words, the hook cannot be released except by two forces acting substantially at right angles to each.

other, one substantially horizontal force operating the plunger and thev other a vertical force operating the hook arm. `As .clearly shown inthe drawings,l considerableclearance isleft between the upper end ofthe safety latch bar andthe ledge 10. This clearanceis of insuicient amount to permit release of the hook from the tongue 24, yet is sucient to permit slight movement of the hook arm, thus allowing it tol clear certain track-` side obstructions withoutfdanger of damaging .the hook mechanism.

While the improved latch arrangementhas.

been described more or less in detailwith' specific reference to two forms, yit will bev obvious` that various ,modifications'and arrangements of parts dening my invention, g Y f What isclaimedis: 'l -1.A A dump car comprising,

impossible" for the Y Vspaced apart lading. retaining Walls, doors-closing the space between avec Lonelo.thedocrsinclbsed posit-io andanauto-l matically operated-- safety 1ste-h ica red; wholly by said: maiaiatcn and engageabie 'with e fixed y"part door 'retaifnihgfpo'sition-- l 2'; A dump caricomprlsingspaced'apart lading retain-mg wan-s', fdeersgelosing the' space between maticallyv operated ,safety latch-normally .holding 1 said' mairrdatch' inv doonretaini-ng positiomsaid safety latch being mounted orrsaidrnzatin` latch andy movable therewith after" being released.

` f 3".' IA`V` dump car comprising',v spaced`r apart lading t 'n'ing'V walls, doors clcsin'g'` the 'space between s'aidf walls landl hinged" toswingr downwardly to discharge' the ladingof the car, a: main' latch carried by the car4 and nornially `retaining'at` least oneYof"'tln'efdocrs inl closed'iposition, said main tienf era substantially vertically actin-gione, and a safety latch normallyA blockingmovement of 'saidmainlatch and'operable upon application carried by the car and normally retaining at least one ofthe doors in closed position, said main latch moving to release the door upon application of a substantially vertically acting force, and a safety latch normally blocking movement of said main latch and operable upon application of a substantially horizontally acting force to release the main latch for movement, said safety `latch being mounted on said main latch and engaging a iixed part of the car to lock said main latch f in door retaining position.

5. A dump car comprising, spaced apart lading retaining walls, doors closing the space between said walls and hinged to swing downwardly to discharge the lading of the car,a hook engaging at least one of the doors to retain the same vin closed position, a latch arm pivotally mounted on the car and carrying said hook and formed with a hollow end portion, a safety llatch bar pivotally mounted on said latch arm and having one part extending into said hollow end portion and another part extending laterally to engage a lixed part of the car to lock said latch arm and hook in door retaining position, ,and .plunger means slidable within said hollow arm and operable to swing said safety latch vbar out of engagement with said xed part of the car.

6. A dump car comprising, spaced apart lading retaining walls, doors closing the space between said walls and hinged to swing downwardly to discharge the lading of the car, a hook enf gaging at least one of the doors to retain the same in closed position, a latch arm pivotally mounted `on the car and carrying said'hook and formed with a hollow end portion, a safety latch bar pivotally mounted cn said latch arm and having one part extending into said hollow end por` tion and another part extending laterally to engage a xed part. of the car to lock said latch arm and hook. in door retaining position, and plunger means slidable 4withint said hollow arm and-cperable te swing. seidietenfberiot efengagement with saldi; fixed'l part ofi the; car,

anni rand niovable tcwardd ori releasing' position l independently of door `'xnaybemoved tocloscd-position irrespecing retaining walls, .doors `closingfthe space be u l tween'fsaidi walls and-'hinged 'to swing down?.

wardly to discharge the lading of-A the car; a latch arm piyotally carriedbyfthefcarand a hook for retaining e doer-iin mused pennen andbeing' pvetairycarried by said .latent arm andF movable relative-thereto. l 'j i l i 81. A diimpcar"comprisinggspaced apartlad-fV ingureta-ining wallsjdoors closingthe space be-` tween said walls an-d' hinged to swing downwardly to: discharge t-he'lading of" the car, a latch arm pivotallycarried bythe car; a hook pivotally ciarfy ried by sai-df latch va1,mf and' movableerelative thereto under action .of a .closing door., and Aspring 1 means interposed v betweenparts-foi",said arm. .and

dbonen'gagingposition. 9.` A dump car comprising,'spaced,apart lading retaining walls, doors' closing thefspace be.- tween said wallsand 'hinged to swing downwardly to discharge the lading ofthe car, a latch arm pivotally carried by the car, a hook for retaining a door in closed position and being pivotally carried by said latch arm and movable relative thereto, and asafety latch preventing accidental operation of said latch arm to release the door. 10. A dump carcoinprising, spaced apart ladmg retaining walls, doors closing the space be,- tween said walls and hinged to swing downwardly to discharge the lading of the cara main latch hook and constantly urging said hook toward carried by the car and directly retaining at least one of the doors in closed position, said main latch `including a latch arm land a hook engageable by the door, safety means preventing accidental movement of said latch arm, and means permittiin1 re l{ative movement between said latch arm an oo when the latter is c i the closing doorY a ted upon by 11. In a device of the character described, the

combination of a dump car having spaced apart ladlng retaining walls 'l between the walls and vhinged to swing downwardly to discharge the lading of the car, a main latch carried by the car and retaining at least one of the doors in' closed position, a safety latch v said main latch, and

carried by the carand normally preventing movement of said main latch, means for operating additional means for operating sald safety latch and holding the same in released position during operation of latch by said iirst named means.

12. In a device of the character described, the combination of a dump car having spaced apart lading retaining walls and doors closing the space between the walls and hinged to swing downwardly to discharge the lading of the car, a main latch carried by the car and retainingat least one of the doors in closed position, a safety latch carried by the car and normally preventing movement of said main latch, 'means for lifting a part of said main latch to release said one door'for opening/movement, and means acting axially of said main latch part to operate Asaid safety latch prior to lifting of said main latch part. y

13. In a device of the character described, 4the combination of a dump car having spaced apart lading retaining walls and doors closing the space and doors closing thespace i said main ,one

` Y .ra-erases between the 3 vvallfs;,and hinged. to swing down- 'vvardl tovdischargegthejadingrof the'car, N,an main latchv arried bythe-cargand retaining atrfleast said f afretylatchprior to the'moving of said main` latzch'byfsaidsrst named.means. l i

ylading 'retaining ,Walls and doors closingthe space` between the Walls and hinged to Asvvingldown- Wardly to discharge vthe -lading l ofA the car, a mainlatch lcarriedA .by the car and-retaining at l astfne` of the doors in closed position, a safety latch.' carried ,by the carand normally prevent-' ing movement of said :nain latch, means acting in fthedcors lin ,closed position, a-saiety latch "ca dbthe carlandnormally preventing movement of said .main-latch, ,means for lmoving -Vsaid n main,gllatclritor release .said one door .for opening;

movement', and additional means acting. upon al part ,associated `With said main latch4 to operate 14; device l. of the ,character described,A`r the; comb ation 1 ofA` a Y dump-.car having' A spaced apart' wallsto forma lading` retaining bodyl and being movable to an open position to #discharge lading .from/the body, a main latch carried b-y the-car 1l for normally retaining at least one of "the ,doors in closed'position and movabletoreleased position permitting movementofthe door toy an open position, andan 'automatically operatedl safety latch normally retaining said mainrlatch in door retainingy position and'movable yin tljieY plane'cf saidfmain vlatch `to 'a released position permitting movement ofysaidmain latch toreleased posimovable to `al1/,openposition to discharge lading rf 'onedirection,fu'p'onV apart ofvsaid main latch to j Amoi/efthe@same A,and release said .onedoor for opening mOi/ement, and'.'additional means acting another direction to'voperate ysaid safety latch prior to movement of said main latchl part to ref` lease said one door.'V l y llljlljdiixnp car comprising', spaced apart lading retaining Walls, doorsvcooperatingwith said 16.I A comprising, spacedapartladingrretainin'g WallsV ,doorsv cooperatingywith said walls toformfa lading retainingbody and being 

